In this link in this thread there's talk about "echos" when referring to 375ml beer bottles.
As in "Bottle trees are also a good idea as you can store 60-70 echo's (sic) on it and it can save space."
How many people still call them echos? I think this is a peculiarly South Australian term, and I assume it's because you used to take the "echo" back and get a refund.
Thoughts and experiences, anyone?
Oliver